A. Poiares Baptista

Proliferating Trichilemmal Cyst

Fourteen eases (9 female, 5 male) of proliferating trichilemmal cysts are reported The patients age‐range was 40–80, 12 being over 60. The cysts were present for 2–50 years and enlarged in the months or years before the observation. Seven were ulcerated. In 4 with multiple lesions both proliferating and ordinary trichilemmal cysts were present. The histological features were typical in all but one patient (evolution towards squamous cell carcinoma?) with some variation from lesion to lesion and from area to area in the same tumour. The microscopic features suggest that the proliferating trichilemmal cyst must be considered an hamartoma of the terminal hair follicle, not only related to the isthmic segment of the outer root sheath but with some differentiation (smaller and more variable) towards the infundibular and matricial segments. The tumour is likely to be a proliferating trichilemmal cyst from the beginning and not a peculiar evolution of an ordinary, pre‐existant, trichilemmal cyst.

Trichilemmal carcinoma : review of 8 cases

Clinical and hislological data from 8 trichilemmal carcinomas are reviewed. The tumors occurred mainly on sun‐exposed skin of the face of elderly people as small solitary, frequently ulcerated nodules. Histologically, they consisted of multilobulate, infiltrative growths, connected to the epidermis and piloscbaceous structures and showing features reminiscent of the outer root sheath of the hair follicle. The presence of lobules of clear, glycogen‐rich cells with peripheral palisading, hyaline basement membranes, trichilemmal keratinization, and abortive follicular sheaths and the absence of ductal or acinar differentiation allow distinction from other clear cell tumors of the skin. Although the histological picture suggests a high‐grade malignant neoplasm, trichilemmal carcinoma has an indolent course. No recurrence or metastases have been observed.

Experimental studies on the mechanisms of tiaprofenic acid photosensitization

Red blood cell lysis and histidine degradation, photosensitized by tiaprofenic acid (TIA), were investigated. Photohaemolysis was markedly enhanced in oxygenated solutions, but was also intense in the presence of nitrogen. Photohaemolysis was inhibited by butylated hydroxyanisole and reduced glutathione, but was unaffected by sodium azide, superoxide dismutase and mannitol. The TIA-induced photo-oxidation of histidine was greatly enhanced in the presence of oxygen and almost completely inhibited in solutions bubbled with nitrogen. Sodium azide, butylated hydroxyanisole and reduced glutathione inhibited the photodegradation of histidine. Phototoxicity to histidine was unaffected by mannitol and superoxide dismutase. The overall results suggest that molecular mechanisms involving free radicals and singlet oxygen are responsible for TIA-photosensitized reactions. These two in vitro models (photohaemolysis and histidine degradation) represent different mechanisms of phototoxicity, but complement one another in the investigation of potential phototoxic substances.

Childhood cutaneous mucinosis.

A case of childhood cutaneous mucinosis is described. This is a clinical condition that is rarely seen and has only recently been included in the group of primary mucinosis.

Papular‐purpuric “gloves and socks” syndrome

Papular‐purpuric “gloves and socks” syndrome is a recently isolated acute self resolving disease. It is characterised by symmetrical cutaneous lesions on the hands and feet, with a sharp limit at the wrists and ankles, presenting a gloves and socks look. Lesions begin as a pruritic oedema and erythema and turn purpuric. Oral mucosal lesions, high fever and arthralgia are also present. Parvovirus B19 has been implicated in this exanthematic disease in about 50% of the cases. We recently observed two typical cases of this syndrome; only one patient had serologic evidence of recent infection by Parvovirus B19.